JTAG Command Support with Security Enabled

and s support additional bitstream security by letting you disable JTAG commands completely or partially:

  • JTAG Disable—Permanently disables the JTAG efuse instruction as well as all other JTAG commands except for the ones used to read device information.
  • JTAG Disable Efuse—Permanently disables the JTAG efuse instructions only. Other JTAG instructions are not affected, for example, you can still perform debugging.

The following table shows the commands supported for each mode.

Table 1. Allowed JTAG Commands with Security Enabled
Command JTAG Disable JTAG Disable Efuse
Ti35, Ti60, , , , Ti90, Ti120, Ti180, , , , , , , , , Ti90, Ti120, Ti180, , , , , ,
BYPASS
DEVICE_STATUS
EFUSE_PREWRITE
EFUSE_USER_WRITE
EFUSE_WRITE_STATUS
ENTERUSER
EXTEST
IDCODE
INTEST
JTAG_USER1
JTAG_USER2
JTAG_USER3
JTAG_USER4
PROGRAM
SAMPLE/PRELOAD
USERCODE
Refer to the following topics for details: